The demand for versatile and sustainable energy materials is on the rise, given the importance of developing novel clean technologies for transition to a net zero economy. Here, we present the synthesis, characterization, and application of lignin-derived ordered mesoporous carbons with various pore sizes (from 5 to approximately 50 nm) as anodes in sodium-ion batteries. We have varied the pore size using self-synthesized PEO--PHA block copolymers with different PEO and PHA chain lengths, applying the "soft templating" approach to introduce isolated spherical pores of 20 to 50 nm in diameters.
View Article and Find Full Text PDFProducts of lipid peroxidation induce detrimental structural changes in cell membranes, such as the formation of water pores, which occur in the presence of lipids with partially oxidized chains. However, the influence of another class of products, dicarboxylic acids, is still unclear. These products have greater mobility in the lipid bilayer, which enables their aggregation and the formation of favorable sites for the appearance of pores.
View Article and Find Full Text PDFAmphiphilic copolymer self-assembly is a straightforward approach to obtain responsive micelles, nanoparticles, and vesicles that are particularly attractive for biomedicine, i.e., for the delivery of functional molecules.
View Article and Find Full Text PDFDeveloping highly efficient semiconductor metal oxide (SMOX) sensors capable of accurate and fast responses to environmental humidity is still a challenging task. In addition to a not so pronounced sensitivity to relative humidity change, most of the SMOXs cannot meet the criteria of real-time humidity sensing due to their long response/recovery time. The way to tackle this problem is to control adsorption/desorption processes, i.
View Article and Find Full Text PDFChemical co-precipitation from ferrous and ferric salts at a 1:1.9 stoichiometric ratio in NHOH base with ultrasonication (sonolysis) in a low vacuum environment has been used for obtaining colloidal suspensions of FeO nanoparticles coated with citric acid. Before coating, the nanoparticles were processed by electrohydraulic discharges with a high discharge current (several tens of amperes) in a water medium using a pulsed direct current.
View Article and Find Full Text PDFThe amyloidogenic self-assembly of many peptides and proteins largely depends on external conditions. Among amyloid-prone proteins, insulin attracts attention because of its physiological and therapeutic importance. In the present work, the amyloid aggregation of insulin is studied in the presence of cholesterol-based detergent, Chobimalt.
View Article and Find Full Text PDFElectrodepositing insulating lithium peroxide (LiO) is the key process during discharge of aprotic Li-O batteries and determines rate, capacity, and reversibility. Current understanding states that the partition between surface adsorbed and dissolved lithium superoxide governs whether LiO grows as a conformal surface film or larger particles, leading to low or high capacities, respectively. However, better understanding governing factors for LiO packing density and capacity requires structural sensitive in situ metrologies.
View Article and Find Full Text PDFThe structural integrity, elasticity, and fluidity of lipid membranes are critical for cellular activities such as communication between cells, exocytosis, and endocytosis. Unsaturated lipids, the main components of biological membranes, are particularly susceptible to the oxidative attack of reactive oxygen species. The peroxidation of unsaturated lipids, in our case 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), induces the structural reorganization of the membrane.
View Article and Find Full Text PDFThe development of lipid nanoparticles requires knowledge on the crystalline structure, polymorphic transitions and lipid-drug interactions. This study aimed at introducing advanced techniques to characterize nanostructured lipid carriers (NLC) comprising palmitic acid, oleic acid, stabilizer and Domperidone. Crystallinity of single components and mixtures was investigated by laboratory Small Angle X-ray Scattering (SAXS).
View Article and Find Full Text PDFLow-density lipoproteins (LDL) are natural lipid transporter in human plasma whose chemically modified forms contribute to the progression of atherosclerosis and cardiovascular diseases accounting for a vast majority of deaths in westernized civilizations. For the development of new treatment strategies, it is important to have a detailed picture of LDL nanoparticles on a molecular basis. Through the combination of X-ray and neutron small-angle scattering (SAS) techniques with high hydrostatic pressure (HHP) this study describes structural features of normolipidemic, triglyceride-rich and oxidized forms of LDL.
View Article and Find Full Text PDFThis work is focused on a novel class of hybrid materials exhibiting enhanced optical properties and high surface areas that combine the morphology offered by the vinyl substituted silica host, and the excellent absorption and emission properties of 5,10,15,20-tetrakis(-methyl-4-pyridyl)porphyrin-Zn(II) tetrachloride as a water soluble guest molecule. In order to optimize the synthesis procedure and the performance of the immobilized porphyrin, silica precursor mixtures of different compositions were used. To achieve the requirements regarding the hydrophobicity and the porous structure of the gels for the successful incorporation of porphyrin, the content of vinyltriacetoxysilane was systematically changed and thoroughly investigated.
View Article and Find Full Text PDFThis paper extends the study of the induced temperature change in the mesostructure and in the physical properties occurring in aqueous mixtures of the ionic liquid 1-ethyl-3-methyl imidazolium octyl-sulfate [EMIm][OSO4]. For some compositions, these mixtures undergo a phase transition between the liquid (isotropic in the mesoscale) and the mesomorphic state (lyotropic liquid crystalline) at about room temperature. The behavior of mixtures doped with a divalent metal sulfate was investigated in order to observe their applicability as electrolytes.
View Article and Find Full Text PDFSelf-emulsifying drug delivery systems (SEDDS), often intended for oral delivery, are normally explored in biorelevant aqueous media. The high complexity of these multi-component systems leaves the understanding of self-emulsification poor, hindering formulation rationalization. In this work, we aimed to fill this gap by studying the effects of glycerol on the self-emulsification of a ternary component formulation made of 20% w/w Tween 80, 15% w/w Span 80, and 65% w/w Captex 300 Low C6.
View Article and Find Full Text PDFThe interactions of irbesartan (IRB) and irbesartan-2-hydroxypropyl-β-cyclodextrin (HP-β-CD) complex with dipalmitoyl phosphatidylcholine (DPPC) bilayers have been explored utilizing an array of biophysical techniques ranging from differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), ESI mass spectrometry (ESI-MS) and solid state nuclear magnetic resonance (ssNMR). Molecular dynamics (MD) calculations have been also conducted to complement the experimental results. Irbesartan was found to be embedded in the lipid membrane core and to affect the phase transition properties of the DPPC bilayers.
View Article and Find Full Text PDFWe present the first report on the effects of hydrostatic pressure on colloidally stabilized lipid nanoparticles enveloping inverse nonlamellar self-assemblies in their interiors. These internal self-assemblies were systematically tuned into bicontinuous cubic (Pn3m and Im3m), micellar cubic (Fd3m), hexagonal (H), and inverse micellar (L) phases by regulating the lipid/oil ratio as the hydrostatic pressure was varied from atmospheric pressure to 1200 bar and back to atmospheric pressure. The effects of pressure on these lipid nanoparticles were compared with those on their equilibrium bulk, nondispersed counterparts, namely, inverse nonlamellar liquid-crystalline phases and micellar solutions under excess-water conditions, using the synchrotron small-angle X-ray scattering (SAXS) technique.
View Article and Find Full Text PDFThe thermal and structural evolutions associated to active pharmaceutical ingredient (API) purity are monitored using a laboratory instrument (S3-MicroCaliX) allowing simultaneous time-resolved X-ray scattering at both wide and small angles (SWAXS) as a function of temperature. This is performed simultaneously with differential scanning calorimetric (DSC) that is carried out in the same apparatus at scanning rate of 2 K/min on the same sample in the range from 20° to 200°C. We have studied simultaneous thermal and structural properties of pentoxifylline, as an active pharmaceutical ingredient (API), for its purity quality control.
View Article and Find Full Text PDFOP-145, a synthetic antimicrobial peptide developed from a screen of the human cathelicidin LL-37, displays strong antibacterial activities and is--at considerably higher concentrations--lytic to human cells. To obtain more insight into its actions, we investigated the interactions between OP-145 and liposomes composed of phosphatidylglycerol (PG) and phosphatidylcholine (PC), resembling bacterial and mammalian membranes, respectively. Circular dichroism analyses of OP-145 demonstrated a predominant α-helical conformation in the presence of both membrane mimics, indicating that the different membrane-perturbation mechanisms are not due to different secondary structures.
View Article and Find Full Text PDFMacrolide antibiotics, such as azithromycin and erythromycin, are in widespread use for the treatment of bacterial infections. Macrolides are taken up and excreted mainly by bile. Additionally, they have been implicated in biliary system diseases and to modify the excretion of other drugs through bile.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2011
Superparamagnetic nanoparticles were prepared by coprecipitation of ferrous (Fe(2+)) and ferric (Fe(3+)) aqueous solution by a base. Nanomagnetite particles were coated with poly(St/PEG-EEM/DMAPM) and poly(St/PEG-MA/DMAPM) layer by emulsifier-free emulsion polymerization. Chemical structure of nanoparticles was characterized by both FTIR and (1)H NMR.
View Article and Find Full Text PDFSelenium appears to be an important protective agent that decreases cadmium-induced toxic effects in animals and plants. The aim of these studies was to investigate the changes of properties of chloroplast membranes obtained from Cd-treated rape seedlings caused by Se additions. Chloroplasts were isolated from leaves of 3-week-old rape plants cultured on Murashige-Skoog media supplied with 2 microM Na(2)SeO(4) and/or 400 microM CdCl(2) under in vitro conditions.
View Article and Find Full Text PDFSynchrotron small-angle X-ray scattering (SAXS) was applied for studying the effects of hydrostatic pressure and temperature on the structural behavior of fully hydrated tetradecane (TC)-loaded monoolein (MO) systems. Our main attention focused on investigating the impact of isobaric and isothermal changes on the stability of the inverted type discontinuous Fd3m cubic phase as compared to the inverted type hexagonal (H(2)) liquid crystalline phase. The present results show that compressing the TC-loaded Fd3m phase under isothermal conditions induces a significant increase of its lattice parameter: it approximately increases by 1 A per 75 bar.
View Article and Find Full Text PDFBackground: The potential physiological significance of the nanophase transition of neutral lipids in the core of low density lipoprotein (LDL) particles is dependent on whether the rate is fast enough to integrate small (+/-2 degrees C) temperature changes in the blood circulation.
Methodology/principal Findings: Using sub-second, time-resolved small-angle X-ray scattering technology with synchrotron radiation, we have monitored the dynamics of structural changes within LDL, which were triggered by temperature-jumps and -drops, respectively. Our findings reveal that the melting transition is complete within less than 10 milliseconds.